The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Energy supply systems of different designs for supplying power to electrical loads of a vehicle are already known from practical experience in vehicle engineering. Often, the electrical loads arranged in a distributed manner in the vehicle are supplied by means of a multiplicity of individual electrical leads, which are bundled into a set of leads and, starting from a generator, a vehicle battery and/or a power distributor, are routed through the vehicle to the loads. During vehicle production, these leads are laid at the rather late stage in the installation space that then remains in the vehicle, e.g. in sills, cavities or niches. Here, the ground return from the loads to the electrical negative terminal of the vehicle battery is accomplished via the electrically conductive body of the vehicle, from which a ground conductor is passed to the negative terminal of the vehicle battery.
For the sake of lightweight construction of a body, however, use is also made of different material combinations, which are often not suitable for ground return via the body manufactured therefrom, owing to the low electrical conductivity and/or the joining technique between the individual materials thereof. This is because the ground return current always follows the path of least electrical resistance, but it is not possible to predetermine this clearly in the case of different material combinations and various joining techniques. Moreover, it has been found that the ground return current is also dependent on its frequency, higher frequencies bringing about a ground return current which is particularly difficult to calculate. Owing to the undefined or undirected ground return current, electromagnetic fields which have a negative effect on the electromagnetic compatibility (EMC) of the vehicle can arise.
Another kind of ground return is known, for example, from the German patent application with the application number 102014005001.7, which is a later publication. This document contains a description of a ground return for a body made from a carbon-fiber-reinforced plastic (CFRP), which is electrically nonconductive or only slightly conductive. Owing to the poor electrical conductivity of the CFRP body, this prior art proposes to directly integrate a ground conductor designed as a flat conductor rail into the CFRP body by lamination into the CFRP material of which said body is made. Although this allows a ground return even in the case of a nonconductive body, there is a desire for a ground return which is simpler in design and/or in terms of manufacture.